The present invention relates to a commercial warewasher or dishwasher, and more specifically to an apparatus for facilitating removal of the wash arm.
Commercial warewashers typically employ a wash arm or nozzle-equipped manifold for spraying water at high temperature and pressure at target dishware. Such machines recycle the wash water, so that food particles are often included in the high pressure flow. Often dislodged particles collect on the wash arm and other washer components, and when exposed to the soapy water, heat and humidity of the interior of the machine, a residue forms on the wash arm and other components. Thus, the wash arm ideally is removed for cleaning on a regular basis to maintain operational efficiency of the warewasher. In heavy commercial use situations, daily cleaning is recommended.
U.S. Pat. No. 4,257,559 describes a conventional mechanism for removing the wash arm including a threaded closure cap which is mounted on a threaded rod which is coaxial with the wash arm. To remove the wash arm, the operator backs off the closure cap from the rod to create a clearance between the cap and the corresponding wash arm end. The clearance allows the removal of the wash arm. However, it has been found that the accumulated grime in the machine makes it difficult for the operator to move the cap after use, and grime often clogs the threads. Also, the configuration of the cap is not conducive to positive gripping by the operator. Thus, tools are often required to free the cap for efficient wash arm removal. Because of the difficulty in removing the wash arms, they may not be cleaned as frequently as recommended.
Another approach to removing the wash arm is disclosed in U.S. Pat. No. 5,927,616. A spring-biased rod exerts an axial clamping force on the wash or rinse arm (the terms are used interchangeably) during operation. When arm removal is desired, a “T”-shaped handle is used to retract a clamping rod against the spring force. The handle is pulled to a temporary open or retracted position where the spring is compressed, releasing clamping pressure on the wash arm and enabling removal. However, since the spring is exposed to the washing chamber of the warewasher, it is subject to becoming covered with grime, which interferes with retraction.
Thus there is a need for an improved apparatus for easily removing a wash arm from a warewasher, and which provides sufficient clamping force for holding the wash arm in an operational position. There is also a need for such an improved wash arm retainer which is less susceptible to accumulation of grime than conventional units.